There is known a configuration in which a gap hiding board hiding a gap between a rear seat and a luggage floor of an automobile is hinged to a front end of the luggage floor (JP-A-2014-4881). The gap hiding board is normally brought into a state by biasing in which it stands obliquely against a rear surface of a seat back of the rear seat described above. The gap hiding board is configured to follow the movement in which a backrest angle of the seat back is changed.
In the configuration in which the gap hiding board stands obliquely against the rear surface of the seat back as in the above-described prior art, a luggage space becomes narrower by the overhang of the gap hiding board.